Centimetre

A centimetre (the American spelling is centimeter, symbol cm) is a unit of length in the International System of Units (SI) measurement system. It is equal to one hundredth of a metre. Centi- is placed in front to say 'a hundredth'. The centimetre is the base unit of length in the old centimetre-gram-second (CGS) system of units.

The centimetre is usually used to measure things that are too big for millimetres but too small for metres. A centimetre is close to the length of a fingernail.